Hydrogen-induced sp2-sp3 rehybridization in epitaxial silicene
Date
2017Source Title
Physical Review B
Print ISSN
2469-9950
Publisher
American Physical Society
Volume
96
Issue
23
Pages
235423-1 - 235423-6
Language
English
Type
ArticleItem Usage Stats
194
views
views
204
downloads
downloads
Abstract
We report on the hydrogenation of (3×3)/(4×4) silicene epitaxially grown on Ag(111) studied by in situ Raman spectroscopy and state-of-the-art ab initio calculations. Our results demonstrate that hydrogenation of (3×3)/(4×4) silicene leads to the formation of two different atomic structures which exhibit distinct spectral vibrational modes. Raman selection rules clearly show that the Si atoms undergo a rehybridization in both cases from a mixed sp2-sp3 to a dominating sp3 state increasing the distance between the two silicene sublattices. This results in a softening of the in-plane and a stiffening of the out-of-plane phonon modes. Nevertheless, hydrogenated epitaxial silicene retains a two-dimensional nature and hence can be considered as epitaxial silicane. The level of hydrogenation can be determined by the intensity ratio of the Raman modes with different symmetries. © 2017 American Physical Society.